assignment 8

MSRSAS - Postgraduate Engineering and Management Programme - PEMP

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ASSIGNMENT

Module Code ESD 525

Module Name Real Time Software Engineering

Course M.Sc in Real time embedded systems

Department Computer engineering

Name of the Student Bhargav Rajivbhai Shah

Reg. No CHB0911001

Batch Full-Time 2011.

Module Leader Deepak Vardam

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M.S.Ramaiah School of Advanced Studies Postgraduate Engineering and Management Programmes(PEMP)

#470-P Peenya Industrial Area, 4th Phase, Peenya, Bengaluru-560 058

Tel; 080 4906 5555, website: www.msrsas.org

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Declaration Sheet Student Name Bhargav Rajivbhai Shah

Reg. No CHB0911001

Course Real time embedded systems Batch Full-Time2011

Batch Full-Time2011

Module Code ESD 525

Module Title Real Time Software Engineering

Module Date 8.11.2011 to 3.12.2011

Module Leader Deepak Vardam

Extension requests: Extensions can only be granted by the Head of the Department in consultation with the module leader.

Extensions granted by any other person will not be accepted and hence the assignment will incur a penalty.

Extensions MUST be requested by using the „Extension Request Form‟, which is available with the ARO.

A copy of the extension approval must be attached to the assignment submitted.

Penalty for late submission Unless you have submitted proof of mitigating circumstances or have been granted an extension, the

penalties for a late submission of an assignment shall be as follows:

Up to one week late: Penalty of 5 marks

One-Two weeks late: Penalty of 10 marks

More than Two weeks late: Fail - 0% recorded (F)

All late assignments: must be submitted to Academic Records Office (ARO). It is your responsibility to

ensure that the receipt of a late assignment is recorded in the ARO. If an extension was agreed, the

authorization should be submitted to ARO during the submission of assignment.

To ensure assignment reports are written concisely, the length should be restricted to a limit

indicated in the assignment problem statement. Assignment reports greater than this length may

incur a penalty of one grade (5 marks). Each delegate is required to retain a copy of the

assignment report.

Declaration The assignment submitted herewith is a result of my own investigations and that I have conformed to the

guidelines against plagiarism as laid out in the PEMP Student Handbook. All sections of the text and

results, which have been obtained from other sources, are fully referenced. I understand that cheating and

plagiarism constitute a breach of University regulations and will be dealt with accordingly.

Signature of the student Date

Submission date stamp (by ARO)

Signature of the Module Leader and date Signature of Head of the Department and date


iii

Abstract ____________________________________________________________________________

Software engineering is the way to address users requirements applying right methods,

techniques and tools to create quality software which is reliable, extensible and maintain the

complex software. To maintain the quality of the software development some process, steps or

models are required. there are two models are available. One is CMM and another is ISO.

CMM which is created for software industries and ISO which is created for wide range

of industries are used as reference. As part a of this assignment survey is prepared on the

applicability of ISO and CMM model and compared both model briefly.

The main objective of part B and part C is perform the structured analysis and object

oriented analysis to the Digital video recorder.UML modeling and SART have been applied to

DVR and effectively explain the differences between the two approaches. And also discuss

design technique to develop Real time embedded system.

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Contents ____________________________________________________________________________

Contents

Declaration Sheet ......................................................................................................................... ii Abstract ...................................................................................................................................... iii Contents .......................................................................................................................................iv List of Figures .............................................................................................................................. v List of Symbols ............................................................................................................................vi

List of Tables ............................................................................................................................. vii

PART-A ......................................................................................................................................... 8

CHAPTER 1 .................................................................................................................................. 8 1.1 Introduction ......................................................................................................................... 8 1.2 characteristics of CMM and ISO ......................................................................................... 8 1.3 Comparison & analysis of CMM and ISO standard ............................................................ 9

1.5 Conclusion ......................................................................................................................... 10 PART-B ...................................................................................................................................... 11

CHAPTER 2 .............................................................................................................................. 11 2.1Introduction ........................................................................................................................ 11 2.2 Functional Requirements for DVR ............................................................................... 11

2.2.1Requirement ID and cross reference ........................................................................... 11 2.3 Non-Functional Requirements ...................................................................................... 12

2.4Entity Relation Diagram ..................................................................................................... 12

2.5 Data Flow Model: .............................................................................................................. 13

2.5.1 Context Diagram ........................................................................................................ 13 2.5.2 Level 1 DFD ............................................................................................................... 14 2.5.3 Level 2 DFD ............................................................................................................... 15

2.6 PSPEc for DVR ................................................................................................................. 16

2.7 Data dictionary .................................................................................................................. 18 2.8 Control flow diagram ........................................................................................................ 19 2.9 Test cases for DVR ............................................................................................................ 19

PART-C ...................................................................................................................................... 22 CHAPTER 3 .............................................................................................................................. 22

3.1 Introduction ....................................................................................................................... 22 3.1 Use case Analysis .............................................................................................................. 22

3.2 Actors: ............................................................................................................................... 22 3.3 Use case Description: ........................................................................................................ 22 3.4 Use Case Diagram ............................................................................................................. 25 3.5 Component design ............................................................................................................. 25

3.5.1 Class diagram: ............................................................................................................ 26

3.6 Capsule structure diagram ................................................................................................. 26 3.7 Behavioral Diagrams ......................................................................................................... 26 3.8 Results Discussion ............................................................................................................. 30

CHAPTER 4 .............................................................................................................................. 33 4.1Learning Outcome .............................................................................................................. 33 4.2Conclusion .......................................................................................................................... 33

REFRENCE ............................................................................................................................... 34 BIBILOGRAPGY ..................................................................................................................... 35


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List of Figures ____________________________________________________________________________

Figure2.1 ER diagram for DVR ................................................................................ 13 Figure2.2 Context level diagram of DVR ................................................................. 14

Figure2.3 Level 1 DFD ............................................................................................. 15 Figure2.4 Level 2 DFD ............................................................................................. 16

Figure2. 5 CFD for DVR ........................................................................................... 20

Figure3.1 Use case diagram ...................................................................................... 25 Figure3.2 Class diagram for DVR ............................................................................. 27 Figure3.3 Capsule structure diagram for DVR.......................................................... 28

Figure3.4 Behavioral diagram for displaymenu capsule .......................................... 29 Figure3.5 Behavrioral diagram for control capsule ................................................... 29

Figure3.6 Behavirial diagram for recordnow capsule ............................................... 30 Figure3.7 Behavirioul diagram for schedule capsule ................................................ 30

Figure3.8 Test result-1 .............................................................................................. 31 Figure3.9 Test result-2 .............................................................................................. 31 Figure3.10 Test result-3 ............................................................................................ 32

Figure3.11 Test result-4 ............................................................................................ 32


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List of Symbols ____________________________________________________________________________

Symbol Description

CMM

ISO

FR

NFR

DVR

ERD

Capability Maturity Model

International standard organization

Functional requirement

Non functional requirement

Digital Video recorder

Entity relation diagram

DFD

PSPECs

MMC

USB

OOD

UC

TSN

C

TS

SEI

Data flow diagram

Process Specifications

Multimedia card

Universal serial bus

Object Oriented Design

Use case

Test case Number

Critical

Test Strategy

Software engineering institute

.


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List of Tables ____________________________________________________________________________

Table1.1 General comparison ...................................................................................................... 10

Table2. 1 FR_01 .......................................................................................................................... 11 Table2. 2 FR_02 .......................................................................................................................... 11 Table2. 3 FR_03 .......................................................................................................................... 12 Table2. 4 FR_04 .......................................................................................................................... 12 Table2. 5 FR_05 .......................................................................................................................... 12

Table2. 6 FR_06 .......................................................................................................................... 12 Table2.7 PSPEc for “RS_main” .................................................................................................. 17 Table2.8 PSPEc for “S_REC” .................................................................................................... 17 Table2.9 PSPEc for “PL_TV” ..................................................................................................... 17

Table2.10 PSPEc for “U_REG” .................................................................................................. 17 Table2.11 PSPEc for “CH_STO” ................................................................................................ 18 Table2.12 Data dictionary for “Functional detail” ...................................................................... 18 Table2.13 Data dictionary for “Storage media detail” ................................................................ 18

Table2.14Data dictionary for “Recording schedule detail” ........................................................ 18 Table2.15 Data dictionary for “operations live TV” ................................................................... 19 Table 2.16 Data dictionary for “operation for recorded video” .................................................. 19

Table2.17 Test cases for DVR .................................................................................................... 21

Table3. 1 Capsules present in the DVR ...................................................................................... 26

PART-A

CHAPTER 1

1.1 Introduction

The development of software includes the creation of specification, design, source code, and

testing. These different artifacts interact with each other where a delay or defect in one affects the

completeness of the others. This often results in a software product that is behind schedule, over

budget, nonconforming to requirements and of poor quality. Controlling and improving the process

used to develop software is seen as the remedy to these problems. The use of standards in the

control the quality of the information system development process is the good solution to maintain

the quality of software. There are two standards. One is ISO and another is CMM.

CMM is a result of developing a process maturity framework in 1986 by SEI(Software

Engineering Institute) . CMM offers a meaning for gradual development in the maturity of

software process. There are five levels of increasing process states:-Initial, Repeatable, Defined,

Managed, Optimizing.

The international organization ISO has developed a series of standards for quality assurance

and quality management, collectively known as the ISO 9000. The ISO 9000 standards are

reviewed and updated once every 5-8 years. The standards released in the year 2000 are known as

ISO 9000:2000. ISO 9000 to ISO 9004 are standards for quality control for design, analysis, testing,

and implementation phases present in the software development.

1.2 characteristics of CMM and ISO

CMM

CMM Model presents a theory on quality levels of software which are well recognized

and are in good pace with industry standards. Any organizations could go on with different levels of

CMM to achieve greater levels of quality.[1] There are five levels in CMM.

The first level of the software development process, referred to simply as the initial level, is

described as ad hoc, poorly controlled, and often with unpredictable results in terms of schedule,

effort, and quality. At level 2, the repeatable level, the outputs of the process are consistent (in

terms of schedule, effort, and quality) and basic controls are in place, but the processes that produce

those results are not defined or understood. Level 3, the defined level, is the point at which the

software engineering practices that lead to consistent output are known and understood and are used

across the whole organization. The managed level, or level 4, is where the defined elements from

level 3 are quantitatively instrumented so that level 5, the optimizing level, can be achieved. Level


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5 exists in organizations in which the development process operates smoothly as a matter of routine

and continuous process.

ISO

ISO 9000 describes the elements of a quality assurance system in general terms. These

elements include the organizational structure, procedures, processes, and resources needed to

implement quality planning, quality control, quality assurance, and quality improvement. However,

ISO 9000 does not describe how an organization should implement these quality system elements.

Consequently, the challenge lies in designing and implementing a quality assurance system that

meets the standard and fits the company‟s products, services, and culture.

The establishment of policy and objectives by an organization to manage resources.

The assignment of responsibilities and authority to staff.

The development of an organizational structure among the staff.

It accommodates different service delivery types.

It maintains service user focus.

ISO standards link well into a service delivery setting.

1.3 Comparison & analysis of CMM and ISO standard

The Capability Maturity Model (CMM) is a process, used to develop and refine software

development process. ISO is a systematic study to monitor whether the method used to improve

quality.

In general, the CMM and ISO 9000 address similar issues and have the common concern of

quality and process management [3]. The origin of each framework is clearly different. The ISO

focus is the customer-supplier relationship, attempting to reduce a customer's risk in choosing a

supplier. In contrast, the CMM strength is the attention on the software supplier to improve its

internal processes to achieve a higher quality product for the benefit of the customer.

The ISO 9000 standard is written for a wide range of industries other than software. Hard-

goods manufacturing was the original focus for this specification. The CMM framework was

created from the ground-up to be specific to the software industry.

The CMM has more depth that the ISO standards. The ISO 9000‟s concept is to follow a set

of standards to make success repeatable. The CMM is an on-going process of evaluation and


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improvement, moving from one level of achievement. Even at the highest level of maturity in

CMM, the focus is on continuous improvement.

Score CMM Score ISO

Stability high high

Scope of model average average

Area of application high average

Ease of application average high

Availability of tools average average

Availability of experience average high

Ease of gradual improvement high low

Ease of Presenting result high average

Degree of acceptance low high

Table1.1 General comparison

1.5 Conclusion

Based on the above discussion i can conclude that ISO and CMM are somewhat same and

widely used in industries.ISO is the good option for general quality and process management. But

in the case of software organization, The CMM is preferable.


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PART-B

CHAPTER 2 ________________________________________________________________________________

2.1Introduction

In this part of assignment is structured analysis which applied to DVR system and a

document is produced by with the list of all requirements.

2.2 Functional Requirements for DVR

a. Supports the user to enter time and date of session ,channel and length to be

recorded.[FR_01]

b. Able to play, replay or fast forward live T.v channels.[FR_02]

c. Supports the user to start and stop record session of channel on unscheduled time by

pressing dedicated buttons for each.[FR_03]

d. Should able to play recorded videos. [FR_04]

e. Supports user to enter choice to escape commercials or fast forwarding in recorded

videos.[FR_05]

f. Allow the user to copy the recorded videos from one storage media to another storage

media.[FR_06]

2.2.1Requirement ID and cross reference

Req_ID FR_01

Description In this case , device should support user to enter time

,date ,channel and length to be recorded.

Cross Ref.

Table2. 1 FR_01

Req_ID FR_02

Description In this case,device should able to play,replay,fast forwad

live T.V channels.

Cross Ref.

Table2. 2 FR_02

Req_Id FR_03

Description In this case ,user should able to record T.V programs from live

Streaming.

Cross Ref. FR_02


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Table2. 3 FR_03

Req_ID FR_04

Description In this case, user should able to play recorded videos

from selected storage media.

Cross Ref. FR_01,FR_02

Table2. 4 FR_04

Req_ID FR_05

Description In this case, user should able to make a choice to escape

commercials or fast forward the video.

Cross Ref. FR_04

Table2. 5 FR_05

Req_ID FR_06

Description In this case, user should able to copy recorded vides from

source storage device to destination storage device.

Cross Ref. FR_01,FR_03

Table2. 6 FR_06

2.3 Non-Functional Requirements

a. Should be accurate.[NFR_01]

b. Should be power effective.[NFR_02]

c. Should be capable user friendly.[NFR_03]

d. Should be robust.[NFR_04]

e. Should be compact .[NFR_05]

2.4Entity Relation Diagram The Entity-Relationship (ER) Model defines the relationship between the entities present in the system.

The entities have set of attributes. The entity presets in DVR are as follow:

a. User - it‟s a basic need of the DVR to get controls from user. Needed for FR_01, FR_02,

FR_03, FR_04, FR_05, and FR_06.

b. Controls for live TV - It is controls for live TV option. It‟s a weak entity that is depending

upon the user. Needed for FR_02.

c. Controls for recorded video play - It‟s a controls for recorded video. It‟s a weak entity that is

depending upon the user. Needed for FR_04,FR_05.

d. DVR- It‟s a basic need for the DVR system. It will work according controls given by the user.

Needed for FR_01, FR_02, FR_03, FR_04, FR_05, and FR_06.


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e. Antenna –It‟s a basic need for DVR for receiving the TV signal .Needed for FR_01, FR_02,

and FR_03.

Figure2.1 ER diagram for DVR

2.5 Data Flow Model:

The data flow model depicts the flow of the data within the system. The pictorial

representation is called the Data Flow Diagram (DFD) which consists of processes which are

described using Process Specifications (PSPECs), the data itself is described using the Data

Dictionary.

The DFD has many levels of construction. The LEVEL 0 DFD is called a Context Diagram. The

DFD is further refined in more levels of DFD so as to understand all the flows in the system. This

refinement is stopped when procedural/implementation details are began to be described.

2.5.1 Context Diagram

Fig 2.2 includes all the External Entities identified as a part of the DFD construction

process. The identified External Entities include:


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User: user is the external entity to DVR control process. User will provide process ID and process

parameter to DVR process. According to that process ID and parameter DVR will function.

Receiving antenna: Transmitted T.V signal will generate polarization on the antenna. Due to this

polarization antenna will generate a signal .that will be the input signal for DVR.

Storage media: this represent different kind of storage media which is use to store video or play

the stored video.

Figure2.2 Context level diagram of DVR

2.5.2 Level 1 DFD

There are five main processes in the in DVR, Which are describing below. The Context diagram

has been refined to produce the Level – 1 DFD.

Schedule for recordings: this process is responsible for memorizing user‟s schedule and record

from appropriate channel and time slot. Input of this process is schedule entered by user. Output is

the

Recorded appropriate video on the selected storage media.

Play live TV: this is process which will take responsible for live telecast of T.V channels. This

process is initializes by user according to users wish.


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Unscheduled recording: this is the process which is responsible for record form live T.V. this is

not pre scheduled recording. This process will initiate by user. Output of this process will be

recorded slot between start and stop pressed by user.

Change storage media ID: This process is used to flip storage media for recording or the playing

of video. This process will be invoked by the user. As the output of this process appropriate storage

media will be configure as default.

Play recorded video: this process is responsible for playing recorded video from the selected

storage media. Output of this process will be recorded video on screen.

Figure2.3 Level 1 DFD

2.5.3 Level 2 DFD

The Level – 2 DFD for the DVR is as shown in Figure 4. The Level – 1 data flow diagram has been

refined to produce the Level – 2 DFD.


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Set schedule: In this process will ask for Date, time, channel and length to be recorded.

Live TV: This process is responsible for live TV functions. As a sub part of this faction user can

play, forward and pause live T.V.

Figure2.4 Level 2 DFD

Recorded video: This process is responsible for the functions related to manipulation of recorded

video. There are five function attached with this process .which are play recorded video, stop

recorded video, pause recorded video, and skip commercials

Change storage media: This is a process which is useful to configure different types of storage

media with DVR. There are various storage media is hard drive, USB stick and MMC.

Unscheduled recording: This process is responsible for recording without scheduled. As a sub

process of this main process there are two processes are there start and stop unscheduled

recordings.

2.6 PSPEc for DVR

PSPEc is used to describe process specification in DFDS. In DFD level 1 there are five processes

which is describe below as.


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Requirement tag ID RS_main

Discription Input Process ID with user.

Process This is Leven 0 DFD for DVR. There are two entities are

present. One is user who is using DVR. Other is receiving

antenna which receive s the TV signal. And storage media

is attached with DVR to save recordings.

output User gets required output.

Table2.7 PSPEc for “RS_main”

Requirement tag ID S_REC

Description Input Time, Date and Duration of recording from user.

Process This will memories recording schedule provided by user.

And according to schedule it records the videos.

output Recorded video on selected storage media.

Table2.8 PSPEc for “S_REC”

Requirement tag ID PL_TV

Description Input Appropriate process ID from user to invoke this function.

Process This will play Live T.V. There are Play, forward , and

pause function attached with this function for live T.V.

output Live T.V on screen.

Table2.9 PSPEc for “PL_TV”

Requirement tag ID U_REC

Description Input Appropriate process ID from user to invoke this function.

Process This is a process which is responsible for unscheduled

recording. Which will initiated by user.

output Recorded video on selected storage media.

Table2.10 PSPEc for “U_REG”

Requirement tag ID CH_STO


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Description Input Appropriate storage media ID from user.

Process This process will configure different king of storage media

with DVR. And select the default storage media.

output Configuration and Selection of default storage media.

Table2.11 PSPEc for “CH_STO”

2.7 Data dictionary

Data dictionary is the representation of data flow in the system. It helps to understand data model

more clearly. The data dictionary for DVR is shown as.

Name Function detail

Aliases Function_ID

Where\how to use function detail provided by user

Description Information about which function user wants to do

Format Alphanumeric

Table2.12 Data dictionary for “Functional detail”

Name Storage media detail

Aliases Storage_ID

Where\how to use storage media configuration detail provided by user

Description Information about which storage media user wants to access or select

as recording destination

Format Alphanumeric

Table2.13 Data dictionary for “Storage media detail”

Name Recording schedule detail

Aliases Schedule_detail

Where\how to use Recording schedule detail which is provided by the user

Description Information about schedule which user wants to record

Format Alphanumeric

Table2.14Data dictionary for “Recording schedule detail”

Name Operations for live TV

Aliases Ctr_TV


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Where\how to use Live TV options which will select by user

Description This is play, forward, pause options with will selected by user.

Format Numeric

Table2.15 Data dictionary for “operations live TV”

Name Operations for recorded videos

Aliases Cte_rvid

Where\how to use Recorded video options which is selected by user

Description This is forward, skip commercials operations which is selected by the

user.

Format numeric

Table 2.16 Data dictionary for “operation for recorded video”

2.8 Control flow diagram

The control flow diagram shows the flow of control within the system. The Control Flows

are super imposed on the existing final level DFD. When there is a control flow it is depicted in

terms of dotted arrows. It can be seen that user flows the data or control information to invoke

process. Similarly processes send control information to hardware for the sake of their functioning.

Figure 2.5 shows the CFD for DVR.

2.9 Test cases for DVR

Test cases are designed to test functionality of system. This are mainly checks the developed

product is confirms to its requirement. Table 2.17 shows the test cases which are to be performed

on system. The test cases are based on the functional requirements. The last column to be filled only

after the product is developed and running code is available to testing.


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Figure2. 5 CFD for DVR

TCN FR Feature C Test cases TS Test Data Expected

results

TC_1 FR_02 DVR must

able to play,

pause and

forward live

TV channels

Y

Checking if

DVR is able

to play TV

and process

channels

Black

box

Power on

button

should play

pause and

forward TV

channels

TC_2 FR_01 DVR should

maintain and

record

according to

user‟s

schedules

Y

Checking of

Schedule

recordings

function of

DVR

Black

Box

By entering one

recording

schedule

Should

record video

of schedule

duration and

selected

channel


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record

unscheduled

programs

Y

Checking of

unscheduled

recording

function

Black

Box

By pressing

button for start

unscheduled

recording

Should

record the

video till

end is

pressed


copy recorded

video from

source to

destination

Y

Checking of

copy

recorded

video from

source to

destination

storage

media

Black

Box

By copying one

video to various

storage media

Should copy

video from

one source

to another

TC_5 RF_05 DVR should

skip

commercial

or fast

forward

recorded

video

Y

Checking of

skip

commercials

and fast-

forward in

recorded

video

function

Black

Box

By pressing

dedicated

buttons for both

function

Should skip

commercials

and fast

forward

recorded

video

Table2.17 Test cases for DVR


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PART-C

CHAPTER 3 ________________________________________________________________________________

3.1 Introduction

In this part the concepts of Object Oriented Design (OOD) are applied to analyze and

implement the DVR discussed and a specifications document is produced along with the

requirements, design strategy and the results are tested according to the test cases discussed in the

section 2.8.

3.1 Use case Analysis

The use case analysis is used to identify the various actors acting upon the system and the

various use case present in the system. The use case helps us to identify whether the functionalities

given by the user is satisfied or not. The following are the various use cased found for the digital

video recording system. They are as follows:

a. Control T.V

b. Schedule

c. Record now

d. Auto record video

e. Control recorded video

3.2 Actors: The actors are the external units that interact with the system. The actors may be person, or

thing, or any entity that take part in the system. The following are the various actors that take part in

the digital video recording. They are as follows:

a. User

b. T.V

c. Antenna

d. DVR

3.3 Use case Description:

Use case 1

Use Case name : Control tv

Use Case ID : UC_1

Actors : T.V , user, Antenna

Purpose : To control the T.V programs

Overview :


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This use case is initiated when the T.V is power on. The user has remote control

over the television. The television runs by getting the signal from the antenna. When the user

switch on the television, the user has full control over the television. The user can play, switch to

another channel, pause, forward video etc…

Precondition : the T.V must switch on

Post Condition : it sends signal to record channel.

Use case 2

Use Case name : Schedule

Use Case ID : UC_2

Actors : TV , user , DVR

Purpose : To schedule the time for recording of video

Overview :

This use case is initiated when the schedule option is selected. In this use case, the

user can schedule the programs to record. The user is allowed to select one channel among the

available channel and length of the program may vary from one hour. The schedule usecase

automatically records the various programs scheduled in the list.

Precondition : the schedule control must be selected

Post Condition : it sends a signal to auto record channels.

Use case 3

Use Case name : Record now

Use Case ID : UC_3

Actors : TV, user, DVR

Purpose : To record the T.V programs instantly

Overview :

This use case is initiated when the record now signal received. this use case will

start recording instantly and it will record until the stop button is pressed. The recorded video is

saved on the selected memory device. Even if the user is not seeing that channel, it will continue

recording for the maximum of length one hour.

Precondition : The DVR must receive record signal

Post Condition : It sends control signal to control recorded video


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Use case 4

Use Case name : auto record video

Use Case ID : UC_4


Purpose : To auto record the programs

Overview :

This use case is initiated when schedule recording is selected and record signal is

received from the schedule use case. This use case will automatically record the videos in the

scheduled time for the pre-given time in minutes. Even if the user is not available at the scheduled

time, once the T.V is switched on the DVR automatically records the video.

Precondition : A record signal from schedule use case

Post Condition : it sends control signal to control recorded video

Use case 5

Use Case name : control recorded video

Use Case ID : UC_5


Purpose : To control the recorded videos

Overview :

This use case is initiated control signal is received either from the auto record or

record or from the user input. This use case shows all the recorded videos and supports the user to

see the various videos. The user can control the videos by pause, play, fast forward, backward

copying to disc etc..

Precondition : A control signal must be received

Post Condition : it resumes the live channel.


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3.4 Use Case Diagram

Figure3.1 Use case diagram

3.5 Component design

In this section components of system are designed. Classes, capsules, protocols are identified

and the Class Diagram and the Capsule structure diagram are drawn. There are four capsules are prese

nt. There are no identified classes. Table 3.1 shows the capsules.

To take recording schedule from

user

Memories the

schedule given by

user

Class\capsule Purpose Attribute

to display menu on screen and

taking user‟s choice for

functions

None


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Table3. 1 Capsules present in the DVR

3.5.1 Class diagram:

The class diagram is used to define the various attributes of the entities and the operations

that satisfy the user requirement . The class diagram contains the relationship which may be of one

of the following such as aggregation, composition, generalization or specialization.

The figure 3.2 shows the class diagram of DVR.

3.6 Capsule structure diagram

Capsule structure diagram shows the interaction between capsules. The capsule interacts

using the ports. Figure 3.3 shows the capsule structure diagram for DVR.

3.7 Behavioral Diagrams

The behavioral diagram shows the behavior of the system under some conditions. State

chart diagrams despites the states of the system. Every capsule has a state which is used to

implement the functionally of the system.

For capsules which are shown in table 3.1 the state charts are as figure 3.4 onwards.

To provide for live T.V ,playing

of recorded video and select

default storage media

Read recorded

video from

appropriate

storage media

To Provide start and stop

unscheduled record function

Record the video

on default storage


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Figure3.2 Class diagram for DVR


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Figure3.3 Capsule structure diagram for DVR

For displaymenu capsule

The display main menu consist of one stage as shown in figure 3.4.the control state is further

divided in to seven stages as shown in figure 3.5. These state diagrams show the state of the DVR

under specific input which would be discussed as a part of the results discussion. Recordnow state

will get input from external user. Schedule will get information about time ,date, channel to be

recorded from external user.


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Figure3.4 Behavioral diagram for displaymenu capsule

For control capsule

Figure3.5 Behavioural diagram for control capsule

For recordnow capsule


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Figure3.6 Behavioural diagram for recordnow capsule

For schedule capsule

Figure3.7 Behavioural diagram for schedule capsule

3.8 Results Discussion

The whole system is tested according to the test cases developed in section 2.8.


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For TC_01,TC_02 and TC_03

The figure 3.8 and figure 3.9 execute the TC_01 ,TC_02 and TC_03.

Figure3.8 Test result-1



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For TC_04 and TC_05

While pressing the key for play the recorded video DVR will start to play the video with some

forward, reverse and pause option that is shown in figure 3.10.



Figure 3.10 execute TC_05 which is playing recorded video.Figure 3.11 execute TC_04 which is

copying the video to the different storage media.


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CHAPTER 4 ________________________________________________________________________________

4.1Learning Outcome

This module helped me to understand the approaches of develop Real time software

process. The use of tools such as RRRT has made me understand that representation of the system can

be developed and a working prototype can be presented. I can effectively and decisively apply the right

software process to provide a software solution either for Real Time systems or even for General

Purpose systems.

4.2Conclusion

In chapter 1,a comparison is done between two model one is CMM and another is ISO

which are used for quality management. After seeing various aspect of the both model i can

conclude that CMM is more preferable for software development .

In chapter 2,a structured analysis concept is applied to analyze the requirement of the

system. A model of system is created. Also the test cases were created to check wither developed

system is meeting requirements or not.

In chapter 3, an object oriented concepts are applied to design the prototype of the system

using RRRT tool. And execute the test cases.


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REFRENCE ________________________________________________________________________________

[1] http://www.hpl.hp.com/hpjournal/96aug/aug96a1.pdf

[2] http://www.snyders.us/cmm-iso.htm

[3] http://xprogramming.com/xpmag/xp_and_cmm

http://www.hpl.hp.com/hpjournal/96aug/aug96a1.pdf

http://www.snyders.us/cmm-iso.htm

http://xprogramming.com/xpmag/xp_and_cmm


35

BIBILOGRAPGY ________________________________________________________________________________

1. Deepak v., Real-time Software engineering, Course Notes – M.S.Ramaiah School of

Advanced Studies, Bangalore, November, 2011

2. Roger S Pressman, Ph.D.,Software Engineering – A Practitioner’s Approach, Fifth Edition,

Mcgraw Hill

3. Paulk, M. C., Weber, C., Curtis, B. and Chrissis, M. B., The Capability Maturity Model -

Guidelines for Improving the Software Process, Addison-Wesley,1994.

assignment 8

Technology